The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingAir inlet control servo motor
Components
Removal
Remove blower assembly
Remove the blower (see page ac-203).
Remove air inlet control servo motor (see
page ac-210)
Inspection
Inspect air inlet control servo motor (for automatic air conditioning
system)
Inspect the servo motor operation. ...
Terminals of ecu
Check instrument panel junction block (main body ecu)
Disconnect the ib and ie junction block connectors.
Measure the voltage and resistance of the wire
harness side connectors.
Reconnect the ib and ie junction block connector.
Measure the voltage of the wire harness ...
Rear seat inner belt assembly
Components
Removal
Remove rear seat leg cover
Remove rear no. 2 Seat leg side cover
Remove rear no. 3 Seat leg side cover (w/
rear no. 2 Seat) (see page se-81)
Remove rear no. 3 Seat leg side cover (w/o
rear no. 2 Seat) (see page se-81)
Remove rear no. 4 Seat leg side co ...